Boceprevir based therapy cleared the hepatitis C virus in 70 percent of patients coinfected with hepatitis C and HIV-1

Data Presented at the Infectious Diseases Society of America (IDSA) 2011 Annual Meeting

MONTREAL, Oct. 20, 2011 /CNW/ - Today Merck announced results from a 24-week interim analysis of an ongoing 48-week Phase IIb clinical study evaluating the investigational use of boceprevir (marketed in Canada under the name of VICTRELIS™), the company's first-in-class, oral hepatitis C virus (HCV) protease inhibitor, in combination with peginterferon alpha and ribavirin, for the treatment of chronic HCV genotype 1 infection in adult patients coinfected with HIV-1.  All patients in the study were new to treatment for chronic HCV, on an optimized antiretroviral regimen and had stable HIV-I disease.

"People living with chronic hepatitis C and HIV can be more challenging to treat and less likely to respond to HCV treatment," says Curtis Cooper, M.D., study investigator and Associate Professor of Medicine at the University of Ottawa, Division of Infectious Diseases. "These interim results are very promising because they demonstrate that the addition of boceprevir to standard treatment may increase the likelihood of permanently clearing their hepatitis C infection. We are eagerly awaiting the final results of this trial."

The interim analysis showed that at week 24 of treatment, twice as many patients receiving boceprevir had undetectable hepatitis C virus (HCV-RNA): 70.5 percent (n=43/61) (95 percent CI 59.0, 81.9) of patients receiving boceprevir in combination with peginterferon alfa-2b and ribavirin had undetectable hepatitis C virus (HCV-RNA) compared to 34.4 percent (n=11/32) (95 percent CI 17.9, 50.8) of patients receiving peginterferon alfa-2b and ribavirin alone, a treatment difference of 36.1 percent (95 percent CI 16.1, 56.2). These interim results are being presented for the first time in a late-breaker oral presentation at the Infectious Diseases Society of America (IDSA) 2011 annual meeting in Boston.  Final results from the study are expected in 2012.

"There are thousands of Canadians living with chronic hepatitis C and HIV," says Josée Brisebois, PhD, Director of Medical Affairs at Merck Canada. "Helping patients who are dealing with both chronic hepatitis C and HIV is a critical issue in infectious diseases today. Merck is committed to evaluating the effectiveness of boceprevir in these patients."

About the Study
The primary objective of this ongoing randomized, multicenter, double-blinded for boceprevir, Phase IIb study is to compare the efficacy of boceprevir 800 mg three times daily in combination with peginterferon alfa-2b (P) 1.5 mcg/kg weekly plus ribavirin (R) 600 to 1,400 mg daily to therapy with P/R alone in adult patients coinfected with chronic HCV genotype 1 and HIV-1. Patients were randomized in a 2:1 ratio to the treatment arm with boceprevir plus P/R or the P/R control arm, respectively.

One hundred (100) adult patients with previously untreated HCV genotype 1 infection and stable HIV-1 disease (HIV-RNA less than 50 copies/mL; CD4 cell counts equal to or greater than 200 cells/mm³) were randomized into the study.  Two patients randomized to the treatment arm receiving boceprevir in combination with peginterferon alfa-2b (P) and ribavirin (R) did not receive boceprevir.  Thus, the interim analysis was based on 98 patients who received at least one dose of study drug: 64 patients in the arm receiving boceprevir plus P/R, and 34 patients in the control arm receiving P/R alone.  All patients treated in the study received a 4-week lead-in with P/R alone followed by boceprevir plus P/R or placebo plus P/R for 44 weeks, for a total treatment duration of 48 weeks.

Patients were stratified by cirrhosis (yes/no) and baseline HCV-RNA (less than 800,000 IU/mL vs. equal to or greater than 800,000 IU/mL).  The majority of patients were non-cirrhotic (95 percent), white (82 percent) and male (69 percent), with a median age of about 43 years.  Most patients had high HCV-RNA (88 percent) at baseline and HCV genotype 1a infection (65 percent).

Antiretroviral regimens for HIV-1 that included non-nucleoside reverse transcriptase inhibitors (NNRTIs), zidovudine, stavudine or didanosine were not permitted.  Patients with detectable HCV-RNA and less than a 2 log HCV-RNA decline at treatment week 12 or detectable HCV-RNA at treatment week 24 were considered treatment failures and discontinued all treatment.

Tolerability Profile
Preliminary safety data for boceprevir in combination therapy in HCV/HIV coinfected patients demonstrated a profile similar to that previously observed in patients with HCV mono-infection.  There were no unexpected trends in HIV-RNA viral levels or CD4 cell counts.

The most common side effects of the combination treatment include neutropenia (low number of white blood cells), dysgeusia (bad taste), vomiting, fever, headache and decreased appetite.

Boceprevir Indication in Canada
Boceprevir (VICTRELIS™) was approved for use in Canada in July of this year for the treatment of chronic hepatitis C genotype 1 infection, in combination with peginterferon alpha and ribavirin, in adult patients (18 years of age and older) with compensated liver disease, including cirrhosis, who are previously untreated or who have failed previous peginterferon and ribavirin therapy.

Boceprevir is not indicated for the treatment of chronic hepatitis C in patients coinfected with HCV and HIV-1 in Canada.

Merck's Global Commitment to Advancing Hepatitis Therapy
Merck is committed to building on its strong legacy in the field of viral hepatitis by continuing to discover, develop and deliver vaccines and medicines to help prevent and treat viral hepatitis.  In hepatitis C, company researchers developed the first approved therapy for chronic HCV in 1991 and the first combination therapy in 1998.  In addition to ongoing studies with boceprevir, extensive research efforts are underway to develop additional innovative oral therapies for viral hepatitis treatment.

About Merck
Today's Merck is a global healthcare leader working to help the world be well.  Merck is known as MSD outside the United States and Canada. Through our medicines, vaccines, biologic therapies, consumer care and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to healthcare through far-reaching policies, programs and partnerships. For more information about our operations in Canada, visit www.merck.ca.

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